Top Web Performance Testing Articles

Apica´s Performance Blog is your source for tips, trends and tools for optimizing your web performance. Track current web performance metrics and brenchmarks and new technology in web performance testing.

June 7, 2016

How CDN Companies Measure Latency and Acceleration

Adding server power only improves site server performance to a point: Once server power is maxed out, the physical distance between a site’s host server and the visitor becomes a key component in how long a page takes to load. Content Delivery Networks (CDNs) are a widely used solution to improve load times and performance on websites by decreasing the physical distance data travels.

Not every CDN is created equal, however. Your business may opt to measure latency and acceleration to determine which CDN, if any, best suits the audience.

On Latency

A server’s “megabits per second” performance only tells part of the tale when it comes to load speed. Bandwidth measures how much data moves at once, while latency measures how long that data takes to move from the source to the destination. Ookla Speedtest explains the situation with a pipe metaphor: latency measures how much time it takes for water to enter a pipe and reach the end of that pipe, while bandwidth measures the pipe’s diameter.

Moving large amounts of data, such as app updates, isn’t time-sensitive (in terms of when it starts)—so latency is not an issue here. However, latency is an extremely important performance metric for things like loading web pages, which should at most take only a few seconds.

However, CDNs don’t improve performance for everyone. For example: If the person trying to buy the metaphorical milk lived closer to the dairy farm, going to the store would take longer. Additionally, if the dairy farm and corner store were equidistant from the milk shopper, they would not see a performance boost. CDNs can also help with capacity and bandwidth management.

According to cloud services provider Radware, picking the most effective CDN often requires some market research to identify where a site’s users are located. For example, a site that’s hosted out of Boston and does most of its traffic in the Northeastern and Western United States would benefit more from a CDN that improves load times in Los Angeles, Portland, and Seattle than one that boosts load times in Boston, Beijing, and London.

Acceleration testing data can help businesses make smart decisions when it comes to CDNs. Find out more about how Apica can support your CDN testing process from more than 83 countries and 2,600 monitoring nodes across the globe on our website.